Client validate on blur

For now, the option on which event the validation should be performed is set like this:
```HTML
<form data-ufo='{"validateOn":"keyup"}'>
```

See `http://localhost/client_testing` for a working example (changed the url from /temp to /index to be more in line with `server_testing`).

See one of the issues about this.

(My console told me that this will be a merge by the **recursive** strategy.)